Dual engine powered motor vehicle and control mechanism therefor



F. H. BEALL 2,419,811

M THEREFOR April 29, 1947.

DUAL ENGINE POWERED MOTOR VEHICLE AND CONTROL MECHANIS Filed Jan. 21, 1941 llkflll/IN/IYG CLUTCH 26 v so I INVENTOR.

Glam/Z Patented Apr. 29, 1947 2,419,811 DUAL ENGINE POWERED MOTOR VEHICLE- AND CONTROB' MECHANISMLTHEBIEFORT:

tha lent, eau, netn iflluien. Application January 21, 1941, Serial .No. 375,314 1'? Claims. (Cl. 180-54) The trend in automobile practice is towards the use of higher octane gasoline giving more power 'per 'gallon and today engines have the highest compression ratios in history,

In;l92 5 automobiles averaged about 60,,hrsepower and had compression ratios of 4.34and used fuels of about 55 octane rating. I

In each succeeding year all three of these factors have moved up until todays' current models averageabout 115 horsepower and have compressionratios of 6 66 and the regular grade, of gasoline has an octane value of about 75...

Thisresults inthe fact that even the lowest pripe cars of t da canoutrun even the highest priceear of 1925 and carry the motorist over teenhills With-9 i t e ce si y O'f gear hiftina A still iurther increase in the octane rating is desirable even; at an in crease in the unitcost of gasoline, It has been estimated that an increase elQQzbctam a ol n u din n ne esigned for-its use, give an increase of 40% in mileage at reasonably highsDeMsand probably a. 20j% savings in cost per mile when the higher e a t i ta i e eun his f co rse, if he 'i ei e e fi v as qqemp e eabr ei d eese in average 1101" SEPQW T W a e were:

T er qmese q s Qwer t date er he. cars of 1925 has largely neutlahzedjhe gainin eificiency obtained with the use of the pre ent ieherp i n ee o QIin Qe n fu iey andard ode s f. e ar e ar has e nt l i ed w th a1 5,; er fepowe in ai re p ckeme e e r an and in hre l l ss re e tnm for gear shifting 'At 20 miles an ho-ur this car usesonly 7.51% of it s available power, at 30 miles per hour only 9 73/25 of its power, and atbqmiles an ho ur it usesdes s than one-sixth of its power. The ba l-- anoof the power is in reserve for acceleration and for pull on the hills Or in rough going.

Even 'at a 25% load the gas consumption is about'two-thirds greaterthan at full loadper horsepower output One object of thisinvention is to have this in the form of an,

desirable reserve of power v V auxiliary orbooster e'ngine normally at rest, but who ready at all times to supply its power to the driving" engine whenever necessary and stal ltlyf 7 V ee ew e o ter n n Quleb madam operate over a range of speed of say 10 t 7O l s hourgw i e the m n n ne. l be at s were. ange t m mile rp rheun he o t .wouldbe ea ed to e. pe atinel tit u m ximu s e d at e ut fireintl f twe gines of 72% horsepower were used the steppedup o q e otthe qqste il dded. hat,, h ain n in w uld v i e t e. e u valent ,pow rtof. h rs ower n nebe i ee t e. o-and; '70 milesperhour. A

Since nest .o he. dr vin all Q1'.,,a power 7. less. t a ne-th d of the N e se ewer 1 2.55. horsepower, hi.. at e t lte lWQukL ef i .z f u adhn he. 2 4 q sepewer m t ri siea f a 3%. Qed nl he fx oflrse tq with q e en eew e e .s preesez n ee wnr. m e 0 .1 .29 i real;

AlsQ, nee v z embie torq e he two Y n: gines will not be used on low gear thedriving train' can be correspondingly lightened A i d b ec t t i fi hi fiereteie the present location of the 4 engine, This is accorn; plished' bv'dividing' the crankshaft bf the engine so as to have say; four cylindersdrive eachih alt, takingthe power from each'n ofthe' engine The power rromftne' "fderrea' yIinders WiIi'be transmitted through the clutch and ear box' in the ndrmaiway whilefthe p r from the front j four cylinders will. be geared to an auxiliary shaft; including an over-running clut handthen'geared" to the propllingimean's at thf tra1islnissi0nl "Other and further important: oblictsf of 'fthis invention will'beappaljent no "the ldislo t p c fi zatiqn'ia a i a In" thefdrawing there is shown the divided crankshaftof a n eng niefa deliver their power from bo mat ic oontrol system for the 7 0 v booster component of the e'n in system is a modification ofth e" contro shownjin my copending application Serial Number 287,424ffild July29',1939. M

In the drawing the crankcase is shown at I containing two crank shafts [and 3 withibearings shown at 4'. The ,two'shaft's ;are separated, at 5', and four cylinders with a firing order of "1,3. 2,14, 3 drive each shaft. Asshownkcrankshaftft ;is" that of the main'engine and crankshafti'tis that of the booster engines Crankshaft; 3 hasv mounted thereon the timing gear 6 and is i then connected to. the tclutch iindi cateda'ttl; From the'clutch fthe'power: is transmitted throughithe gearboXiBitothe propeller shaft 9 for transmitting the ower to the'reaii" axle in the normal way.

Crankshaft 2 has mounted thereon timing gear 10.?'Alsqgeared-tothisigearlfliis an idlerge'ar H driving gear |2 mounted on shaft I3. The other end of shaft 13 is connected to an over-running or one Way clutch indicated at H5. The other side of this clutch is connected through gears indicated generally at |5 to the driven shaft for the transmission of the power to the driving wheels. The use of an overrunning clutch allows the booster engine to slow down and stop while the car is in operation and on starting, the booster is allowed to come up to synchronous speed with the driven shaft before being operatively clutched for driving the vehicle.

While the power from the forward crankshaft 2 is shown connected to the driven shaft of gear box 8, as pointed out in my copending application, Ser. No. 287,424, it is obvious it could be con- 4 again comes in contact with fixed terminal and the armature 3| is again drawn down.

If the speed is still further reduced until, say, 10 miles per hour, moveable terminal 21 comes in contact with fixed terminal 30 and the armature 3| is again short circuited by conductors 33 and 42 and the armature rises stopping the booster.

If in this position the vehicle speed is increased, moveable terminal 28 will not come in contact with fixed terminal 30 to again draw down the armature 3| until the speed has increased to, say, 12 miles per hour.

nected to any convenient point to the driving means to drive the vehicle.

The cylinders operating crankshaft 3 are controlled in the usual way and normal driving will be by these cylinders acting as a normal four cylinder engine.

The booster control system consists of a governor 26 driven from the driven shaft or any engine driven part, but preferably some part that operates at a speed proportional to vehicle speed. This governor moves an insulated slide 26 containing contact terminals 21, 28 and 29 making contacts with a fixed contact terminal 36.

The booster ignition and starting circuit is shown as conductors 25, 25 and 25" connected to 'the battery 23 through the ignition switch 2| for the main engine ignition system 2 l' and an auxiliary switch 22 normally closed, but which could be used as a cut-out switch it the booster should fail to function properly.

As shown, conductor 25 is connected through terminals 24 to armature 3|, and spring hinge '40 of relay 32 and hence through conductor 25 to the relay 50 to be described later.

From conductor 25 a conductor 33 is connected to fixed terminal 30. As shown, the fixed terminal 3D is in contact with with moveable terminal 28., -Moveable terminal 28 is connected through conductor 34 to the relay magnetic coil 35 and through resistance 36 to ground, thus whenever fixed terminal 36 moveable terminal 28 and armature is drawn down against the force of the spring hinge 40.

When the armature is down the contact bar 38, insulated from the armature but moveable with it, short circuits terminals 31 and the relay coil is connected to ground by a second parallel circuit through conductor 39.

If in this position the speed of the car is increased to say, above 60 miles per hour but less than '70 miles the slide 26 moves up until the insulated section 4| is opposite the fixed terminal 30.

The armature 3| will, however, remain in the down position due to the circuit from 25 through terminals 31, short circuiting bar 38, conductor 39 001135 and resistance 36.

However, if the speed still further increases, to say, '70 miles per hour moveable terminal 29 reaches the fixed terminal 38. In this position the relay coil 35 is short circuited by conductor 33 and conductor 42 and the armature 3| rises under the force of spring opening the booster ignition circuit at terminals 24 stopping the booster.

If in this position the vehicle speed is reduced the armature 3| remains in the raised position until at 60 miles per hour moveable terminal 28 is in contact with s The conductor 25' is connected to the relay 50 and through the terminals 5| to the conductor 25' leading to the booster ignition system and booster starting circuit 90.

In the drawing relay 50 is shown as controlled by the accelerator pedal 5|. The position of this pedal determines the opening of the main engine throttle and the quantity of gasses flowing through the engine at any given speed and thus the load on the engine. It also controls the vacuum in the intake manifold and other known factors which vary according to accelerator pedal position. As is pointed out in my copending application, the load on the engine could be sensed by such other factors controlled by the accelerator pedal position and would constitute means responsive to the position of the main engine control means.

Accelerator pedal 5| operates an insulated slide containing a contact terminal 52 connected by conductor 53 to conductor 25'. At substantially fully open th'rottle position, moveable terminal 52 makes contact with contact terminal 56. If relay 32 is in down position current fiows through conductor 51, coil 58 and resistance 59 to ground to draw armature 60 down to the position shown to complete the ignition circuit from the battery to the booster ignition.

The drawing down of the armature 66 also short circuits terminals 6 and through conductor 62 makes a circuit from 25", coil 58, and resistance 59 to ground so that when the throttle is released from its substantially fully open position and terminal 52 moves from its contact with fixed terminal 56 the relay armature is held in its down position.

It will remain in this down position until either the booster ignition circuit is broken by the operation of the speed relay 32 or the throttle is released to substantially fully closed or idling position when moveable terminal 52 makes contact with fixed terminal 54. If relay 10 is in the down position as shown the relay coil 58 will be short circuited by conductor 63, contacts 64 and conductor 65' allowing the armature 60 to rise under the force of the spring 66 to open the booster ignition circuit at contact terminals 5|.

However, when two way switch 93 is closed as shown to connect conductor 68 to switch 61 relay 10 can only be closed when the shifter rod 66 in the gear box (not shown) is moved into the position for high gear closing the switch 61 so that the current for the magnetic coil 69 can flow to ground through conductor 68. This is to prevent the booster from being stopped each time the throttle is brought to-the idling position for shifting gears, in any gear other than high gear.

If after reaching high gear with the throttle in idling position, the accelerator pedal is moved down a short distance until moveable terminal 52 makes contact with fixed terminal 55 a circuit is completed from conductor 25', conductor 53, conductor H, coil 59, conductor 68, two way switch 93, switch 61 and shifter rod 66 to ground; If the speed relay" 32 is operated to close the booster ignition circuit thearm'ature 12 will be drawn down closing contacts 65. At the same time, terminals l3 areshort circuited so that there is-a circuit from 25 conductor M, conductor 15, coil 69, conductor 63, two way switch 93, switch 61 and shifter rod 66 to ground so that moveable terminal 52 can move out'of contact with terminal 55 and the armature 12 still-remain in the down position. Thus it can be seen that the booster will not be stopped by the throttle being brought to -idling for the purpose of shifting gears, but as soonas the car is in high gear the moving of the throttle to theidling position will stop' the booster. This is desirable since if at any time the car was traveling between'the speeds of say 10 to?!) miles per hour, with the booster operating and the driver of lever as against the action of the dash pct 88:.

This is the same 'arrangement'shown in my" copending application "above rferr'ed to; For driving heavy trafilc'it'would be preferable "to makethe ground connectionior'relay"!!! dependent" on theca r exceeding "a" given spe d; say 30 mi'lesper hour. This could be simply "arranged byhaving conductor 88 connected through the'two' way "switch 93 to a secondfixed contact terminal '92; corresponding to terminalwf'oper a'tingagaihst' the contact terminal 9 l on th'e'in ceases to need the extra power, such as slowing down for traffic or going over the top of a hill, he can let up on the accelerator pedal and stop the booster. During the shifting of gears, when the booster engine is not stopped, it is necessary to bring the booster engineto idlingat the same time the main engine is brought to idling. This could be done by inter-connecting the throttle of the main engine and booster engine by a direct linkage. However, I prefer to use the manifold pressure of the main engine. Referring to the drawing, a section of the intake manifold of the main engine is shown at 80. Cylinder 8! is connected by conduit 82 so that the vacuum in the intake manifold will operate 3 to move the throttle control lever 85 to the closed position, shown in dotted lines, when the vacuum is high in the intake manifold.

Spring 8d could be so proportioned that the booster throttle would reach the full open position when the vacuum in the manifold approached the minimum and to simultaneously reduce the power of both engines as the main engine throttle was closed.

However, if desired, the spring could be given a permanent compression in the extended position' shown in which case the booster throttle would not be moved until the throttle of the main engine is say largely closed.

Thestarting of the booster could be either by an electric starter the details of which are shown in my copending application No; 287,424, or the starting over-running clutch arrangement also shown therein. Using the electric starting means shown in this application; when the circuit 25, and 25" is energized by the closing of relays 32 and 5d, the starting circuit 36 is also energized and relay 9 3 will be energized, drawing down the startin switch to close a circuit 97 from the battery23 to the booster starting motor 95. As soon as the booster engine has been started, the vacuum in the booster intake manifold 80 will open the vacuum operated switch 95, opening the circuit from the battery to the starting motor.

"If the electric starter were used, it would be desirable to have a second throttle valve in the boost-er intake riser, normallyclosed, but which would be gradually opened as soon as the booster starts. As shown, 36 is a solenoid connected by conductor 87 to the booster ignition conductor 25". Upon energization of conductor 25 by the control system outlined above, plunger 81-is drawn in openingthe booster throttle by means piston 83 against the spring sulated' -slide. "The'purpose of switch 93 willb described later. Contact terminal 91 wouldbe mounted similar "to'con'tact" 28"exc'ept that it would havea rangefrom 30'miles per hour t'othe maximum speedrang'e"oftheslide operation as deter mined' by" the high speed stop tnegom ernor"20; This 'has'been assumed in thabb'v e tube 70 mil'espef hour; "'nusrourtnniovab'le contact terminal 9! would begrohn'ded. ""Witli this a'rrange'ment -re1'ay""15"'would be grounded"sotliatitcould be drawn to the'bl'osed positiononly when the car speed is ab'ov'e3'0 rents per hourjAtall speeds below this speedftlie booster could-not be'stopped'by the throttleoper ationwhen movable terminal'52was brought into contact with fixed terminal 54, corresponding to theidling'position of the'throttle forthe main engine, since relay "iii could notbeoperated'tb draw down the armature l2 topr'ovideabircuit from -25"'through' conductor 53; conductor 63,

contacts 64; conductor '65,"to shortcir'cuit coil 58 of thethrottlecontrolledrelay 50, "to allow the armature 63 to rise,opening the booster 'igni tion -circuit'at contacts 5i; --"I-Iowever, abovethis speed of say 30 miles per hour-a ground connection" isprovidd "for con d-uctor 63 and relay 7!! can be'di'awn to theclosed position whenever movable contact '5? makescoh tact with fixed contact 55'making acirc'uitfrom 25"through-conductor 5 3, conductor 7|", 'coil'fiS, conductor 68, two'way switch 93 to the grounded contact on slide '26 arranged to provide this g'rciund for conductor 68 at all speeds 'above'30 milesper l M I .l V I L Thus with this alternate arrangement a car operating in heavy trafiic' would notstop the booster each time the accelerator was released, but idleit', until itreached a' trafiic condition where speeds 0130 miles per hour or more were permissible or unless the speed drops below,say, 10 miles per hour.

Since for normal open country driving the grounding of coil 69 through conductor 68 by means of switch 6'1, which is closed whenever the car is in high gear, is desirable, and, since in heavy traffic it is desirable to keep the booster operating at all speeds below say 30 miles an hour, both modes of operation could be provided'and'the choice left to the driver according to traffic conditions. This could be accomplished by the simple two-way switch 93 which, in one position, would ground relay 18 through conductor 68 and switch 61 whenever the car is in high gear andfwithth'e switch in its second position, would ground relay it through conductor '68 whenever the car is above, say 30 miles per hour. For normal driving the driver could have the switch to the firstpo'sition and upon entering the orowdedsection ofa booster engine in accordance with put of the main engine.

clutch for coupling it to the propelling means, a

throttle, an ignition circuit, a starting circuit and starting means therefor, and automatic control means responsive to combined speed of a main engine-driven part and the position of said control means for simultaneously energizing said ignition and starting circuits to start the booster engine, open said throttle and engage said clutch,

so that the booster engine assists the main engine in driving the vehicle and means connected with the booster throttle to operate said throttle in response to the operation of said main engine control means to continuously operate the booster throttle either towards the closed or open position as the main engine control means is moved towards no power or full power position and thereby continuously control the power output of the the power out- 2. In combination, in a vehicle having a main engine, control means therefor, a transmission, vehicle drive means,

a booster engine, a clutch for connecting it to said drive means, starting and ignition circuits therefor and control means therefor, comprising a first control mechanism responsive to the speed of the vehicle, a second control mechanism responsive to the position of said main engine control means, said starting and ignition circuits being energized only upon actuation of both said mechanisms and means associated with said second control mechanism to cause it to de-energize said ignition system thereby stopping the booster upon movement of said engine control means to substantially no power position when the transmission is in high gear and means in said last mentioned means associated with said transmission to prevent said second control mechanism from stopping the booster in lower gears.

3. The control means of claim 2 further characterized in the provision of means in said speed control mechanism to prevent the booster from operating below a predetermined minimum vehicle speed to thereby prevent the booster from delivering its torque in the range of speed of low gear operation of said vehicle.

4. The control means of claim 2 further characterized in the provision of means in said speed control mechanism to prevent the booster from operating above a predetermined maximum vehicle speed to thereby prevent excessive speed of said booster engine.

5. In a vehicle, a main engine, a control means therefor, a transmission and drive means for said vehicle, a booster engine, means for connecting said booster engine to said drive means, an overrunning clutch in said connecting means operative to efiect clutching engagement only when said booster engine comes up to synchronous speed and means responsive to the position of said main engine control means and the speed of a main engine driven element for starting the booster engine and bringing it up to synchronous speed and means responsive to the position of said main engine control means for controlling the booster engine during booster operation and means for stopping the booster when the transmission is in high gear and said main engine control means is moved to substantially closed throttle position.

6. The combination, in a vehicle having a main engine, control means therefor, vehicle drive means and a booster engine, a throttle for said booster engine, a clutch for connecting it to said drive means, starting and ignition circuits thereion-and control means therefor co said main engine control means, mechanism responsive to predetermined speeds of a main engine driven element, said starting and ignition booster engine circuits being only energized upon actuation of both said mechanisms to start said booster and clutch it to said drive means, means in said second control mechanism to stop and prevent booster operation above a predetermined maximum speed, means associated with said main engine control means to stop and disconnect said booster and means for cutting out operative functioning of said last means whereby stopping of the booster is dependent solely upon said second control mechanism, and means for rendering said last means inoperative below a second and lower predetermined speed whereby operation of said main engine control means can stop and disconnect the booster only during the range of booster operation between said lower and maximum predetermined speeds. v

'7. The control means of claim 6 further characterized in the provision of means controlled by the position of the main engine control means for bringing the booster engine up to full load whenever the main engine is operating under load and for idling the booster engine whenever the main engine is idled during the period of operation of the booster engine below said lower predetermined speed.

8. The control means of claim 6 further characterized by means responsive to a predetermined position of said main engine control means for controlling the throttle of the booster engine when the starting circuit thereof is energized.

9. The combination of claim 6 further characterized in the provision of means preventing operative connection of the booster engine into the drive means until the booster engine is at synchronous speed. 7 10. In combination, a vehicle having an engine including separate sets of cylinders and control means therefor, a crankcase, two crankshafts therein each independently driven, vehicle drive means, clutching means operable so that said sets of cylinders can jointly deliver their power to said drive means, the cylinders driving one of said crankshafts being operator controlled by a manual control means therefor, and the cylinders driving the other of said crankshafts being automatically controlled according to the position of said manual control means for bringing said automatically controlled crankshaft into operation and clutching it to the vehicle drive means.

11. In combination, a vehicle chassis having a main engine, a control means therefor, a transmission and propelling means, a secondary booster engine, a clutch for connecting it to the propelling means, and automatic means controlled jointly by the speed of a main engine driven part and the position of said main engine control means for controlling the connection or disconnection of the booster engine to the propelling means, said control means being operative after the booster is once connected to prevent said means controlled by the position of said main engine control means from disconnecting said booster during the operation of shifting gears of said transmission, but will operate to disconnect the boosterwhen the ears of the transmission are in their normal high speed driving position.

1 2. In combination, a vehicle chassis having a. mam engine, a control means therefor, a transnu-i 1:: "prising a first control mechanism responsive to the positionoi a second' c'ontr'ol 9 mission and a propelling means, a secondary booster engine, a clutch for connecting it to the propelling means and automatic means responsive to the position of said main engine control means for controlling the connection and disconnection of the booster engine to said propelling means, said automatic means including means for preventing the booster engine after once connected from disconnection from the propelling means during shifting through low gears of said transmission by the operation of said means responsive to the position of said main engine controlled means, but permitting disconnection by the operation of said means responsive to the position of said main engine control means when the gears in the transmission are in their normal high speed driving position and the power of the booster is not required.

13. In combination, a vehicle chassis having a main engine, a control means therefor, a transmission and propelling means, a secondary booster engine normally at rest, a clutch for connecting it to the propelling means, starting means for said booster engine, and automatic means responsive to the position of said main engine control means for controlling the starting of said booster engine from rest and connecting it to the propelling means and also for disconnecting and stopping the booster engine, said automatic means including means for preventing the booster engine from disconnection and stoppage while shifting through low gears of said transmission by the operation of said means responsive to the position of said main engine control means, but permitting disconnection and stoppage by the operation of said means responsive to the position of said main engine control means when the gears of the transmission are in their normal high speed driving position and the power of the booster is not required.

14. In combination, a vehicle chassis having a main engine, a control means therefor and a propelling means, a secondary booster engine, a clutch for connecting it to the propelling means and automatic means responsive to the position of said control means of said main engine for controlling the connection of the booster engine to said propelling means, means in said automatic means for permitting the disconnection of the booster engine from the propelling means by operation of said control means, said automatic means responsive to the position of said control means including means, once the booster engine is connected, for preventing said disconnecting means from disconnecting said booster engine by the operation of said means responsive to the position of the main engine control means until the vehicle has attained a predetermined speed and permitting disconnection when the vehicle has passed said predetermined speed.

15. In combination, a vehicle chassis having a main engine, a control means therefor and propelling means, a secondary booster engine normally at rest, a clutch for connecting it to the propelling means, starting means for said booster engine, and automatic means responsive to said control means of said main engine for controlling the starting of said booster engine from rest and connecting it to the propelling means, means in said automatic means for permitting the disconnection of the booster engine from the propelling means by operation of said control means, said automatic means responsive to the position of the control means of said main engine control means including means, once the booster engine is started and connected, for preventing said disconnecting means irom disconnecting and stopping said booster engine by the operation of said means responsive to the position of the main engine control means until the vehicle has attained a predetermined speed and permitting disconnection When the vehicle has passed said predetermined speed.

16. In combination, a vehicle having a main engine, a control means therefor and propelling means, a secondary booster engine a clutch for connecting it to the propelling means and automatic means controlled jointly by the speed of a main engine driven part and the position of the main engine control means for controlling the connection of the booster engine to the propelling means; said speed control providing a speed range for said booster and means in said automatic means for permitting the disconnection of the booster engine from the propelling means by operation of said control means, said automatic means including means, once the booster engine is connected, for preventing said means responsive to the position of the main engine control means from disconnecting said booster until the vehicle has attained a predetermined speed within the speed range of said booster engine and permitting disconnection thereafter in said speed range above said predetermined speed.

17. The combination of claim 1 further characterized by an intake manifold for said main engine and wherein said means operable in response to the operation of said main engine control means to continuously operate said booster engine throttle comprises a vacuum cylinder connected to said intake manifold of said main engine, a piston therein connected to said booster throttle, said piston being arranged to be operated by the Vacuum in said intake manifold by acting against a spring to continuously move said booster throttle towards closed position as said main engine control means is moved towards no power position and continuously move said throttle towards open position as said main engine control means is moved towards full power position.

FRANK H. BEALL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 902,692 Sherman Nov, 3, 1908 1,889,305 Zerbi Nov. 29, 1932 1,080,624 Diesel Dec. 9, 1913 1,768,530 Short June 24, 1930 1,971,998 Valentine Aug. 28, 1934 891,350 Mascord June 23, 1908 1,121,114 Moore Dec. 15, 1914 FOREIGN PATENTS Number Country Date 127,644 British June 12, 1919 332,301 German Jan. 28, 1921 538,633 British Aug. 11, 1941 

